In recent years, amongst portable terminal devices, such as mobile telephones, devices possessing a GPS (Global Positioning System) function, which displays the position information of users, have emerged. In addition to this GPS function, by providing a function which accurately detects terrestrial magnetism, and a function which detects acceleration, detection of the azimuth and the orientation in three-dimensional space, or the movement direction, of the portable terminal device carried by the user can be performed. In order to provide the functions mentioned above to the portable terminal device, it becomes necessary to integrate physical quantity sensors such as magnetic sensors and acceleration sensors into the portable terminal device. In order to detect the azimuth and the acceleration in three-dimensional space with such physical quantity sensors, there is a need to install a physical quantity sensor chip on an inclined installation surface.
As a physical quantity sensor mentioned above, a variety of devices are currently being provided. For example, as one of these, a magnetic sensor differing to the above-mentioned configuration, where two magnetic sensor chips are installed on a non-inclined installation surface, is known. This magnetic sensor is mounted on a substrate, and possesses a first magnetic sensor chip (physical quantity sensor chip) which responds to the magnetic components of an external magnetic field in two directions (X and Y directions) which are mutually perpendicular along the surface of the substrate, and a second magnetic sensor chip which responds to the magnetic component of the external magnetic field in the direction (Z direction) which is perpendicular to the surface of the substrate. As a result of the magnetic components detected by the pair of magnetic sensor chips, this magnetic sensor performs measurement of the terrestrial magnetic components as a vector in three-dimensional space.
However, since the second magnetic sensor chip is mounted in a state where it is vertically standing with respect to the surface of the substrate, this magnetic sensor has an inconvenience in that the thickness (the height with respect to the Z direction) increases. Accordingly, in order to make this thickness as small as possible, as mentioned above, the physical quantity sensor chip is installed on an inclined installation surface, as disclosed in Patent Documents 1, 2, and 3.
For example, Patent Document 1 discloses an acceleration sensor as a physical quantity sensor. This acceleration sensor is a one-sided beam structure, and is installed with the acceleration sensor chip inclined with respect to the substrate beforehand. Accordingly, the sensitivity in the fixed axial direction corresponding to the inclination direction is highly retained, and the sensitivity in the other axial directions, including the directions along the surface of the substrate, can be decreased.
However, in a conventional physical quantity sensor, since the physical quantity sensor chip is positioned on an inclined installation surface, a sufficient area and height becomes necessary for packaging. Accordingly, there was a limit to compact integration within small portable terminal devices using conventional packaging.
[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. Hei 9-292408.
[Patent Document 2] Japanese Unexamined Patent Application, First Publication No.2002-156204.
[Patent Document 3] Japanese Unexamined Patent Application, First Publication No. 2004-128473.